[azure] blob storage instrumentation

Makefile

@@ -42,7 +42,7 @@ endif
 
 .PHONY: check-vet
 check-vet:
-	@for dir in $(shell scripts/moduledirs.sh); do (cd $$dir && go vet ./...) || exit $$?; done
+	scripts/check_vet.sh
 
 .PHONY: install
 install:

scripts/check_vet.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+set -e
+
+for dir in $(scripts/moduledirs.sh); do
+    (
+      cd $dir
+      # Before go1.13, there was a bug that prevented the toolchain from
+      # finding a module when no buildable files were present.
+      # In go1.14 this is detected and the message states that build
+      # constraints exclude all Go files.
+      go list -json 2>&1 | grep -E 'build constraints exclude|cannot find module' > /dev/null
+      [ "$?" = "0" ] && echo "skipping $dir: no buildable Go files" && exit 0
+      go vet ./...
+    ) || exit $?
+done